--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+(* This file was automatically generated: do not edit *********************)
+
+set "baseuri" "cic:/matita/CoRN-Decl/reals/CauchySeq".
+
+include "CoRN.ma".
+
+(* $Id: CauchySeq.v,v 1.8 2004/04/23 10:01:04 lcf Exp $ *)
+
+(*#* printing IR %\ensuremath{\mathbb R}% *)
+
+(*#* printing PartIR %\ensuremath{\mathbb R\!\not\rightarrow\!\mathbb R}% *)
+
+(*#* printing ZeroR %\ensuremath{\mathbf0}% #0# *)
+
+(*#* printing OneR %\ensuremath{\mathbf1}% #1# *)
+
+(*#* printing AbsIR %\ensuremath{|\cdot|_{\mathbb R}}% *)
+
+include "reals/CReals.ma".
+
+(*#* *Real Number Structures
+%\begin{convention}% Let [IR] be a structure for real numbers.
+%\end{convention}%
+*)
+
+(*
+Require Export R_CReals.
+Definition IR : CReals := Concrete_R.
+Opaque IR.
+*)
+
+alias id "IR" = "cic:/CoRN/reals/CauchySeq/IR.var".
+
+(* NOTATION
+Notation PartIR := (PartFunct IR).
+*)
+
+(* NOTATION
+Notation ProjIR1 := (prj1 IR _ _ _).
+*)
+
+(* NOTATION
+Notation ProjIR2 := (prj2 IR _ _ _).
+*)
+
+include "tactics/Transparent_algebra.ma".
+
+(* begin hide *)
+
+(* NOTATION
+Notation ZeroR := (Zero:IR).
+*)
+
+(* NOTATION
+Notation OneR := (One:IR).
+*)
+
+(* end hide *)
+
+(* UNEXPORTED
+Section CReals_axioms
+*)
+
+(*#* ** [CReals] axioms *)
+
+inline "cic:/CoRN/reals/CauchySeq/CReals_is_CReals.con".
+
+(*#* First properties which follow trivially from the axioms. *)
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_Cauchy.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Archimedes.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Archimedes'.con".
+
+(*#* A stronger version, which often comes in useful. *)
+
+inline "cic:/CoRN/reals/CauchySeq/str_Archimedes.con".
+
+inline "cic:/CoRN/reals/CauchySeq/CauchySeqR.con".
+
+(* UNEXPORTED
+End CReals_axioms
+*)
+
+(* UNEXPORTED
+Section Cauchy_Defs
+*)
+
+(*#* ** Cauchy sequences
+*** Alternative definitions
+This section gives several definitions of Cauchy sequences. There
+are no lemmas in this section.
+
+The current definition of Cauchy ([Cauchy_prop]) is:
+
+%\[\forall \epsilon>0. \exists N. \forall m\geq N. |seq_m - seq_N|\leq\varepsilon\]%
+#for all e>0 there exists N such that for all m≥ N |seqm-seqN|≤ e#
+
+Variant 1 of Cauchy ([Cauchy_prop1]) is:
+
+%\[\forall k. \exists N. \forall m \geq N. |seq_m - seq_N|\leq1/(k+1)\]%
+#for all k there exists N such that for all m ≥ N |seqm-seqN| ≤ 1/(k+1)#
+
+In all of the following variants the limit occurs in the definition.
+Therefore it is useful to define an auxiliary predicate
+[Cauchy_Lim_prop?], in terms of which [Cauchy_prop?] is defined.
+
+Variant 2 of Cauchy ([Cauchy_prop2]) is [exists y, (Cauchy_Lim_prop2 seq y)]
+where
+[[
+Cauchy_Lim_prop2 seq y := forall eps [>] Zero, exists N, forall m >= N, (AbsIR seq m - y) [<=] eps
+]]
+
+Note that [Cauchy_Lim_prop2] equals [seqLimit].
+
+Variant 3 of Cauchy ([Cauchy_prop3]) reads [exists y, (Cauchy_Lim_prop3 seq y)]
+where
+[[
+Cauchy_Lim_prop3 seq y := forall k, exists N, forall m >= N, (AbsIR seq m - y) [<=] One[/] (k[+]1)
+]]
+
+The following variant is more restricted.
+
+Variant 4 of Cauchy ([Cauchy_prop4]): [exists y, (Cauchy_Lim_prop4 seq y)]
+where
+[[
+Cauchy_Lim_prop4 seq y := forall k, (AbsIR seq m - y) [<=] One[/] (k[+]1)
+]]
+
+So
+[[
+Cauchy_prop4 -> Cauchy_prop3 Iff Cauchy_prop2 Iff Cauchy_prop1 Iff Cauchy_prop
+]]
+Note: we don't know which formulations are useful.
+
+The inequalities are stated with [[<=]] rather than with [<] for the
+following reason: both formulations are equivalent, as is well known;
+and [[<=]] being a negative statement, this makes proofs
+sometimes easier and program extraction much more efficient.
+*)
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop1.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_prop2.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop2.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_prop3.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop3.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_prop4.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop4.con".
+
+(* UNEXPORTED
+End Cauchy_Defs
+*)
+
+(* UNEXPORTED
+Section Inequalities
+*)
+
+(*#* *** Inequalities of Limits
+
+The next lemma is equal to lemma [Lim_Cauchy]. *)
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_complete.con".
+
+inline "cic:/CoRN/reals/CauchySeq/less_Lim_so_less_seq.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_less_so_seq_less.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_less_Lim_so_seq_less_seq.con".
+
+(*#* The next lemma follows from [less_Lim_so_less_seq] with [y := (y[+] (Lim seq)) [/]TwoNZ]. *)
+
+inline "cic:/CoRN/reals/CauchySeq/less_Lim_so.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_less_so.con".
+
+inline "cic:/CoRN/reals/CauchySeq/leEq_seq_so_leEq_Lim.con".
+
+inline "cic:/CoRN/reals/CauchySeq/str_leEq_seq_so_leEq_Lim.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_leEq_Lim.con".
+
+inline "cic:/CoRN/reals/CauchySeq/seq_leEq_so_Lim_leEq.con".
+
+inline "cic:/CoRN/reals/CauchySeq/str_seq_leEq_so_Lim_leEq.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Limits_unique.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_wd.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_strext.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_ap_imp_seq_ap.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_ap_imp_seq_ap'.con".
+
+(* UNEXPORTED
+End Inequalities
+*)
+
+(* UNEXPORTED
+Section Equiv_Cauchy
+*)
+
+(*#* *** Equivalence of formulations of Cauchy *)
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop1_prop.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop2_prop.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_prop3_prop2.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop3_prop2.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop3_prop.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Build_CauchySeq1.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_prop4_prop3.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_prop4_prop2.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop4_prop3.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop4_prop.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Build_CauchySeq4.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Build_CauchySeq4_y.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_CauchySeq4.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Build_CauchySeq2.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Build_CauchySeq2_y.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_CauchySeq2.con".
+
+(*#* Well definedness. *)
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_prop_wd.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_prop2_wd.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_wd'.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_unique.con".
+
+(* UNEXPORTED
+End Equiv_Cauchy
+*)
+
+(* UNEXPORTED
+Section Cauchy_props
+*)
+
+(*#* *** Properties of Cauchy sequences
+
+Some of these lemmas are now obsolete, because they were reproved for arbitrary ordered fields$\ldots$#...#
+
+We begin by defining the constant sequence and proving that it is Cauchy with the expected limit.
+*)
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_const.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_const.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_plus.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_plus.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_plus.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_inv.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_inv.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_inv.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_minus.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_minus.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_minus.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_Lim_mult.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Cauchy_mult.con".
+
+inline "cic:/CoRN/reals/CauchySeq/Lim_mult.con".
+
+(* UNEXPORTED
+End Cauchy_props
+*)
+
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